Electric switch.



'F. ROBINSON. ELECTRIC SWITCH. APrLIoATIoN FILED JUNE 17, 1912.

1,073,289. Pate nted Sept. 16,1913.

FREDERICK JAMES ROBINSON, F LACKAWANNA, NEW YORK.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented seat. 1c, 1913.

Application filed June 17, 1912. SerialNo. 784 0421.

To all whom it may concern Be itknown that I, FREDERICK. J. Romn- SON,citizen of the United States, residing at Lackawanna, in the county ofErie and My invention as embodied in a switch forcontrolling the:circuit of a line supplying current of a dangerous voltage has for itsobject to prevent a person, through ignorance or carelessness, fromclosing the switch when said switch shall have been opened for therepair of the line or like purpose. In jury which might otherwise resultfrom current beingthrown into the line while the line is supposed by thelineman to be open is thus prevented.

My invention contemplates means by which the ordinary knife switch,without any change in the switch structure itself,

can be locked against closure, and preferably is automatically lockedagainst closure whenever the switch is thrown to its open position. M'yinvention is thus in the nature of an vattachmentwhich can be used inconnection with any of the well-known types of knife switches.

I For purposes of description, I have shown my invention, in theaccompanying drawings, asembodied in a single-pole, singlethrown knifeswitch of well-known type, and the seve -.1 features of the inventionmay be more readily understood by reference to said drawings, in which--Figure 1' is a' side elevation of the switch in its open position, withthe closed position thereof indicated in dotted lines, an with the lockpartly broken away; Fig. 7 is a plan view of the switch with the switchblade in section; and Fig. 3 is a transverse section of the switch,showing the attach ment in clevatioln Similar letters of reference referto similar parts llironghontthe several views.

in said drawings, 1 is the base-board upon which are mounted theterminal post 2 and the parallel contact plates 3, 3, of the switch. Theknife bl ad c 4; of-the switch is pivoted to th'e'p'ost 2 and is adaptedto be inoved to its closed position oetween the contact plates in theusual manner.

Mounted on the base-board 1 is a lock 5, which may be of ordinaryconstruction, preferably a springlock. The lock is mounted intermediatethe post 2 and the plates 3, 3 with the front end of the lock slightlyto one side of the plane of movement of the blade 4, and with the uppersurface of the lock approximately flush with the edge of the switchblade when the latter is in its closed position, as indicated in dottedlines in Fig. 1. Preferably there is mounted, opposite to the front endof said lock and in parallel relation thereto,'a plate 6. Said plate andthe end of the lock form a guideway for the blade 4. The bolt 7 of thelock when projected into said guideway serves to block the blade 4against closure between the contact plates 3, 3.

Assuming that the. switch is closed, it

may be thrown to its open position in the usual manner. In'case the lockis a springlock, the bolt 7 is thereupon automatically thrust into theguideway between the end of the lock and the plate 6, thus blocking .theblade 1 against closure until. the bolt 7 is withdrawn in the usualmanner by a key 8 inserted in the key-hole of the lock. The lrey 8 is.provided with an insulated handle ,111 order to protect the user thereofduring the act of unlocking the bolt the closure ofthe switch.

My invention thus provides a simple device adapted to be used incombination with the ordinary type of switch without the necessity ofany structural change being, made in said switch, which device will,upon the switch being thrown to its open position, automatically bloclcthe same against accidental or unwarranted closure.

What I claim is:

1. The combination with an electric switch comprising a base-board, aterminal post and contact plates mounted on said base-board, and aswitch-blade pivoted to to permit of 'said post and adapted to be movedinto closure with said contact'plates; of a lock anda plate extending inparallel relation with the front end of said lock, said lock and platebeing mounted on said base-board in such position that said plate andthe front end of the lock form a guideway for said switch-blade, saidlock liming :1 bolt which guideway.

2. The combination with an electric switch comprising a base-board, aterminal post and contact phites mounted on said base-board, and :1switch-blade pivoted to said post and adapted to be moved into closureWith said contact plates; of a lock mounted at one side of the plane ofmovement of the switch blade with the upper surface of the lockapproximately flush with I the edge of said switch-blade when the Int 1ter is in its closed positien, and :1 guide plate mounted upon theopposite side of said se-itch-blutle, said Look and plate forming a.guideway or said switeh-hl'zule said lock having; a bolt which whenprojected, extends into said guidevmy.

In witness whereof I hereunto subscribe.

1m name this 13th day of June, A. 1)., 1912.

FREDERICK JAMES ROBINSON.

I \Vitnesses:

MARY A. CALDWELL, E. LOUISE CALDWELL.

